A data storage system stores and retrieves information on behalf of one or more external host computers. A typical data storage system includes power supply circuitry, a storage processor, and a set of disk drives. The power supply circuitry provides power to the storage processor thus enabling the storage processor to load data into and retrieve data from the set of disk drives on behalf of the external host computers.
There are a variety of approaches to obtaining and servicing a data storage system. For example, a company which is in need of a reliable data storage system with a relatively large operating budget typically purchases a data storage system configured for high availability (e.g., redundant components) and a field service contract for servicing the data storage system. Under the field service contract, a trained field service technician typically visits the data storage system at the customer site to address any problems encountered with the data storage system. For instance, if a disk drive fails, the technician typically travels to the customer site to manually replace the failed disk drive. The data storage system is often configured to allow hot-swapping of the failed disk drive so that the data storage system as a whole remains operational (i.e., “available”) during the disk drive replacement operation.
A company which is in need of a data storage system but which is not fortunate enough to have a relatively large data storage system budget typically purchases a more modest data storage system sacrificing high availability. That is, the company makes a conscious decision not to purchase a data storage system with certain high availability features and not to purchase a field service contract in order to lower operating costs. Here, the company accepts the risk that a failure in certain components of the more modest data storage system may require the customer to lose access to the data storage system for a period of time. For example, if a disk drive fails, the customer may send the data storage system out for servicing, or alternatively call for a technician to make a special one-time visit to the customer site to replace the failed disk drive but at a premium cost or with a relatively long delay since the technician is not under a field service contract.